Time delay device



` July 1,1958

Filed July '7,'1955 B. D. SMITH TIME DELAY DEVICE 3 Sheets-Sheet 1 BY nd-4,

IN VENTOR BLANCHARD D. SMITH ATTORNEY-S` July l, 1958 s. D. SMITH TIME DELAY DEVICE 3 Sheets-Sheet 2 Filed July 7, 1955 INVEI JTOR H W M S D D R A H C N A L B A ORN July 1, 1958 B. D. SMITH TIME DELAY DEVICE 5 Sheets-Sheet 3 Filed July '7, 1955 'Il 'Il 'lll/lll. S

INVENTOR BLANCHARD D. SMITH ATTORNEYS United States Patent I() TIME DELAY DEVICE Blanchard D. Smith, Atlanta, Ga. Application July 7, 1955, Serial No. .520,467 11 Claims. (Cl. 200-33) This invention relates to time delay devices `land more particularly to a time vdelay electrical switch device.

It is frequently desirable ,to .have an electrical switch device which Yprovides a time delay between its actuation and the completion of the switch operation. Por example, a time delay light switch Alocated at the kbottom of :a stairway permits a person to turn the switch to foit position before proceeding 'up 'the stairs, the .switch delaying the opening of the lighting "circuit toria predetermined time sulhcient to give the Yperson Atime to go up the stairs. However, there are other times when the time delay function of the .switch Ais `not needed and, `consequently, it is advantageous to have a time .delay 'switch in which the .time delay operation may be selectively used as desired.

Time ldelay switch devices areknown in which a owable material, such as sand, 'for example, is permitted to flow through an orice at a predetermined rate, as in an hourglass, in such manner as to actuate the switch .device by the weight .ofthe fsand at the completion of a predetermined time. Switch .devices operating :upon this principle are .generally unsatisfactory since the rweight of the sand or other `flowable material is so slightthatthe force which it provides is insutlicientito :suitably yactuate the switch. F or example, sandlilowing througha normal orice for two minutes weights .2 :grams or :less thanlym) of a pound, `which 'produces a force :so .small as to be impractical for operating 'the switch.

Accordingly, it is an object of this invention to provide a time delay device, particularly suitable for luse 'as Van electric switch, which is eflicient and :reliable in operation.

yit is another object of this vinvention to provide an electrical switching device which may be selectively used to provide an immediate .circuit opening A'action or to 'proide a delayed circuit opening as desired.

It lis `another object of this invention .to provide a time delay switch utilizing .the changing level of a owable material, such as sand, `as a time measuring means to control a switching operation, rather than the Weight of the owable material, as in the conventional time delay switch utilizing a flowable material as a timing means.

fit is still another object of thisinvention Vto provideina modified embodiment a time delay switch having a .-rotatable compartment lfor holding the y:flowable material and having a reciprocating lever .member to move .the rotatable compartment to its timing'positions.

In achievement of these objectives, this invention provides a switching device including a rotatable receptacle or blade compartment which carries the movable electrical contact member, the receptacle .beingprovided `on its interior with a lpair of chambers which communicate `with each other through an orice inthe manner .of an hourglass. A flowable material, preferably hourglass sand, is disposed inside the receptacle and may 'flowfrom one chamber to the other through the orifice. The switching device is provided with an operating knob which may be moved to a .time delayposition to cause l2,841,665 Patented July 1, 195s the 'receptacle to move to a position in vwhich the two chambers are vertically aligned with each other so that gravity will cause the sand to ilow from the :chamber in upper position to the lower chamber. Movement of the oper-ating knob to time delay position also cocks a biasing Spring which strongly urges the receptacle to an off position Vin lwhich the switch blade carried by the receptacle is moved out of engagement with stationary conltact members to open the electrical circuit. However, movement of the receptacle to off position is prevented lby a latching means which includes cooperating elements `carried by the movable receptacle 'and by the stationary housing. A follower member is disposed inside the chamber from which the sand is llowing and follows'the downwardly moving level of the sand to finally release the latching means and permit the receptacle to move to foif'position by spring action. 'The switching device is :also so constructed as to permit the switch to be selectively moved directly to o position when it is not desiredfto use the time delay feature.

In a -moditied preferred embodiment of the invention, the rotatable receptacle having the hourglass chambers is moved to delayed cut-olf position by means of a springbiased `pivoted lever -member which carries a movable electrical contact member. A pawl member carried by the lever Vengages a ratchet carried by the rotatable compartment to move the compartment to timing position in which the hourglass chambers are vertically disposed. The pivoted lever is held in delay 4position due to a locking action between another pawl member carried by Vthe lever and the ratchet wheel carried by the rotatable container. A follower member carried bythe rotatable container engages a stationary abutment to prevent furr ther rotation of the container and consequently to prelven't movement of the pivoted contact carrying lever to oit position until the owable material within the Auppermost chamber of the rotatable `compartment has dropped to a predetermined level. When the follower member carried by the container clears the stationary abutment, the lever member is rapidly moved to off position by spring action. Movement of the lever to foft position opens the electrical circuit and also causes the rotatable compartment to be moved through degrees from aposition lin which the hourglass chambers are vertically disposed Yto a position in which they are horizontally disposed.

yFurther objects and advantages of the invention will become apparent Vfrom the following description taken in conjunction .with the accompanying drawings in-which:

.Fig l is a front elevation view .of a switching device in .accordance with the invention showing the cover plate and the operating knob;

`Fig. 2 isa .side elevation view Fis.y '1.;

Fig. .3 is a view in vertical Fig. l;

Fig. 4.is `.a view in vertical section Fig. 3;

Fig. 5 isa -viewin vertical section along line 5-.5 of

of the v*deviceshown in section along line 3-3 of along line 4-4 of Fig 6 is a view in vertical section along line 6-6 `ot Fig. 3.;

Fig. 7,is an .enlarged fragmentary View, partially in section, showing :details of the connection of the following member, inside `the sand chamber, to the latch arms;

the timedelay switch shown in Fig. 8;

Fig. is a view in section along line 10--10 of Fig. 8; and

Fig. 1l is a view in vertical section showing details of the latch member which prevents reverse movement of the rotatable compartment.

Referring now to the drawings, the switching device of the invention is generally indicated at 10 and includes a standard size cover plate 12 through which extends an operating knob 14 having a pair of oppositely disposed pointers 16 and 18, respectively. The cover plate is marked with an olf position 20, which is displaced approximately 30 degrees in a counterclockwise direction from the top center or twelve oclock position, an on position 22, which is displaced substantially 60 degrees in a clockwise direction with respect to the olf position 20, and a delay position 24, which is displaced approximately 120 degrees in a clockwise direction from the on position. Wedge-shaped detents 26 and 28 project outwardly from the surface of plate 12 to hold the control knob in delay position against the force of its biasing spring, as will be explained later in more detail.

The electrical circuit which is controlled by switch 10 K may be turned on by rotating control knob 14 from off VFig. 3) which extends through the surface of face place 12. Sleeve 30 carries at its inner end, behind the rear surface of plate 12, a radially projecting flange 32 which carries at its radially outer end an axially inwardly extending projection 34.

. A stationary housing 36 is disposed behind face plate 12 for receiving the rotatable receptacle or compartment generally indicated at 38 which carries the rotatable switching element. Housing 36 includes a pair of diametrically opposed projecting ear portions 40 and 42, best seen in Fig. 6, for receiving bolt members 44 and 46 which serve to physically connect housing 36 to the rear surface of face plate 12 and which also serve to connect electrical conductors 48 and 50Yto oppositely disposed xed arcuate contact plates 52 and 54, respectively, which are carried by stationary housing 36. Contact plates 52 and 54 extend radially outwardly into ear portions 40 and 42 for attachment to conductors 48 and 50. Contact plate 52 has a raised lip 53 adjacent one of its ends for imparting a snap action to the movable switch blade, as will be explained later.

Projecting from the forward surface of rotatable compartment 38 is a bearing shoulder 56 having at its forward end a pin 58 which is received by a bearing surface of sleeve 30. A hollow bearing sleeve 60 extends rearwardly from the rear surface of compartment 38 and receives a pin 62 projecting forwardly from the inner rear surface of stationary housing 36. Rotatable compartment 38 is thereby supported for rotation at its forward end by pin 58 and sleeve 30, and by pin 62 and sleeve 60 at its rear end. Y

A rotatable switch blade 64 formed of two interleaved elements 66 and 68 is rigidly secured to bearing shoulder 56 for rotation with rotatable compartment 38. Switch blade 64 is engageable with xed contact plates 52 and 54 to complete the electrical circuit through conductors 48 and 50. When the switch is in off position, the rotatable switch blade 64 lies along the axis indicated at 70 in Fig. 6.

A preloaded coil spring 57 having two opposite free ends S9 and 61 is supported on shoulder 56 of rotatable blade compartment 38. Ends 59 and 61 of the spring normally tend to move toward each other.V and to seat on the oppositely disposed notches 65 of a post 63 which extends axially outwardly from the forward surface of compartment 38. Projection 34 on radial flange 32 which moves with control knob 14 is adapted to engage one or the other of the ends 59 and 61 of the spring to thereby impart rotation to the compartment 38 when the control knob is moved in the oli-on or on-off directions or to store energy in spring 57 when the control knob is moved to delay position. A raised rib 67 extends from the forward surface of blade Vcompartment 38 on either side of post 63 to serve as a track upon which the ends 59 and 61 of spring 57 move when they are engaged by projection 34.

As will best be seen in Figs. 3 and 5, compartment 38 is a generally cylindrical member formed of mating front and rear halves 72 and 74. Each of the mating halves is provided on its interior with a pair of ribs 76 and 78 which extend from the outer circumferential wall 80 of the respective compartment half to adjacent the central axis of the compartment. Each compartment half is also provided with apair of ribs 82 and 84 which extend from adjacent the central axis of the compartment to a point spaced approximately midway of the radial dimension of the compartment.

The two compartment halves 72 and 74 are glued together in such manner that the corresponding ribs 76, 78, 82, 84 of the two mating compartment halves abut each other in mating relation to form a sand guide of the hourglass type.

Ribs 76 and 82 together define a sand holding chamber 86 while ribs 78 and 84 together define a sand holding chamber 88. The respective ribs 76, 78, 82 and 84 converge inwardly toward the central axis of the compartment to define. an orifice 90 which provides communication between the chambers 86 and 88 and permits a flowable material 92, which is preferably hourglass sand, to tlow at a predetermined rate from one of the compartments 86 or 88 to the other.

A pair of paddle-like follower members generally indicated at 94 and 96, respectively, are disposed within the respective chambers 86 and 88. Follower 94 includes a follower portion 98 adapted to rest on the upper level of the sand when chamber 86 is in uppermost position, and a generally V-shaped connecting arm 100 which is adapted to straddle the radially outer edge of rib 82 and which is keyed at its o-uter end to a pivotally mova- -ble shaft 102 which extends through and is supported for pivotal movement by the rear wall of compartment half 74. Similarly, follower 96 is provided with a follower portion 104 which is adapted to rest on the upper level of the sand when chamber 88 is in uppermost position, and a generally V-shaped connecting arm 106 which is adapted to straddle the radially outer edge of rib 84. The outer end of arm 106 is keyed to a shaft 108 which is also supported for pivotal movement by the rear wall of compartment half 74.

As will best be seen in the views of Figs. 3, 4 and 7, the end of shaft 102 which extends beyond the rearwall of rotatable compartment 38 has rigidly attached thereto a crank arm 110 having an axially extending projection 112 which serves as a cam follower cooperating with a cam track generally indicated at 114 and disposed within Vthe rearwardly extending projection 117 of stationary housing 36. In a similar manner, a crank arm 119 having an axially extending cam follower projection 121 is carried by the outer end of shaft 108, to which follower 96 is keyed. Y

The manner of securing the paddle-like follower member 94 within the rotatable blade compartment 38 and also of sealing the compartment against the entrance of air and moisture is best seen in Fig. 7. The outer end of arm portion 100 of follower 94 is provided with a pin 128 which is received in a suitable bearing socket carried by the forward wall of compartment half 72. Arm portion 100 is also provided with an axially extending pin portion 132 which is keyed to an axial socket provided in :shaft 102. To seal in .the dry .air and sand, a cone-shaped .rubbersac 134 having thickened ends has Ione of its thickened ends seated on a molded flange 136 which extends inwardly from the inner surface of the rear wall of compartment half 74. The opposite and smallerend of cone 134 is inverted and has its thickened end seated on shaft 102. The thin wall of the cone-shaped rubber sac 134-permits air expansion under temperature change, and the torsional force exerted upon the sac due to the slight rotation of the paddles is negligible. The paddle-like follower 96 is provided with a similar sealing arrangement to that just described for follower 94.

Asbest seen in Figs. 3 and 4, cam track 114 along which cam follower 112 moves during movement of rotary blade compartment 38 is dened on its radially outer boundary 'by the continuous circumferentially extending `surface 116 which forms the inner circumferential wall surface of the rearwardly extending projection 117 of vhousing 36. The radially inner boundary of cam track 114 is formed by the radially outer surface of rib Y118 which extends axially inwardly from lthe inner rear surface of rear housing portion 117. Surface 116 is continuous and extends for a substantially uniform radial .distance from the axis of rotation of blade compartment `38 for a substantial portion of its circumferential length.

vAt one point, surface 116 extends radially inwardly to define an abutment 120 which engages cam follower 112 to lock the rotatable blade compartment against rotation when control knob 14 is moved toward the delay position 24. The continuity of rib 118 is interrupted for a few degrees on either side of abutment 120, as indicated at 123, to permit a limited radialinward pivotal movement of crank arm 118 and cam follower 112 as the level of the sand in the sand compartment drops, thereby permitting cam follower 112 to clear abutment 120.

Rib 118 is positioned at a uniform radial distance from the axis of rotation for substantially the greater part of vits length. When cam follower 112 moves along this `radially uniform portion of rib 118, the paddle-like follower 94 is maintained at the radially outermost limit of its movement, which maintains the follower above the sand in chamber 86 when chamber 86 approaches vertical position, before reaching the discontinuity 123 in rib 118.

To provide a tortuous path for the cam follower 112 after it is released from engagement with abutment 120, the end of rib 118, first engaged by cam follower 112 after it is released from abutment 121), is provided with `a radially outwardly inclined lip portion 124, followed by a radially inwardly extending arcuate portion 126. The tortuous path also includes an arcuate portion 122 of surface 116, portion 122 extending for substantially 45 degrees beyond abutment 126. As will be explained more fully later, this tortuous path for cam follower 112 assists in decelerating blade compartment 38 after cam follower 112 becomes disengaged from abutment 120.

Cam follower 2f. at the end of crank arm 119 cooperates with the cam track in the same manner as just described for cam follower 112 when sand chamber 88 is performing the timing operation.

Description of operation The cycle of operation of the switching device will now be described: when the switch is in off or delay position, control knob 14 is in the position shown in Fig. l in which one of the pointers 16 or 18 points to the ot position 26. ln the same position of the control knob, the other pointer points to delay position 24.

All of the views in the various figures of the drawings indicate the conditions when the switch has been moved to delay position 24 from on position 22, and when the level of the sand in chamber 86 has decreased to a point at which the cam follower portion 112 is almost ready to clear abutment portion 120 to permit blade compartment 38 to move the rotatable switch blade 64 to o position. In olf position, -the switch blade 64 Ylies on axis 70, which lies Ysubstantially 45 degrees in a clock- -wise .direction from the position of switch blade 64 shown Vin the figures.

The operations leading up to this point in the cycle will be summarized:

t the beginning of the cycle of operation which is now about to terminate by the movement of switch blade 64 to off position at the end of the delay period, the pointer 18 was originally in the off position 20. Pointer 18 was moved from off position 20 to on position 22, thereby causing projection 34 of the radially extending iiange 32 vto engage spring end 61. As pointer 18 was moved from the off position .20 toward the on position 22, blade compartment 3S began to rotate in a clockwise direction with respect to the view shown in .the drawings, causing movable blade 64 to move in a 'clockwise direction away from its off axis 70. The movement of pointer 18 is transmitted to blade compartment 38 through the spring V57, since the end Y59 of spring 57 engages post 63 which projects frorn the forward surface of blade compartment 38. During the movement of blade 64 in a clockwise direction toward the on position, blade 66 engages the raised lip 53 on fixed contact plate 52. Engagement of blade 64 with raised lip 53 temporarily restrains further rotation of blade compartment 38 and blade 64. Since pointer 18 continues its clockwise rotation during this restraint of blade 64 by raised lip 53, spring 57 is tensioned, with the result that blade 64 finally moves past raised lip 53 with a snap action and moves to a vposition in which the blade end is disposed adjacent but spaced beyond raised lip 53. In this position of switch blade 64, it electrically connects contact plates 52 and 54.

lf itis desired to turn the switch olic in the conventional manner, with an immediate opening of the electrical circuit controlled by the switch, pointer 18 is moved in a counterclockwise direction 4from on to off During the counterclockwise movement of pointer 18, .projection 34 on ange 32 which moves with the control knob 14 engages spring end S9 and causes spring end 61 to engage notch 65 of post 63 to impart a counterclockwise movement to blade compartment 38 and switch blade-64. ln the counterclockwise movement from on to off position, switch blade 64 is again temporarily restrained by raised lip 53 on yfixed contact plate 52 causing switch blade 64 to move to its olf axis 70 with a snap action.

When switch blade 64 was in off position and located on its oli axis 70, and with 'pointer 18 in olf position, sand chamber 86 was lfull of sand and was tilted downwardly in a position substantially 45 degrees past the vposition occupied by the sand chamber 88 in the view of Fig. 5. ln the movement of the switch from off to on position, the sand .chamber '86 was moved tosubstantially a horizontal, or slightly kbelow horizontal, position.

As the pointer 18 is moved from .the on position 22 to the delay position 24 to provide ka time delay operation of the switch, chamber 86 is moved from a substantially horizontal, or slightly below horizontal, position to the vertical position shown in Fig. 5 in which chamber 86 is disposed vertically above chamber 88. Abutment is sopositioned as Ato stop the movement of blade compartment 38 when the sand chambers 86 and 88 are vertically disposed. Projection 112 engages abutment 120 to prevent further rotation of blade cornpartment 38 before pointer v18 has moved fully into delay position 24. Hence, any further movement of pointer 18 after blade compartment 3S Vhas been locked against further rotation causes a storing of energy in coil spring 57. In `moving into delay position, pointer 13 moves past'the wedge-shaped inclined detents 26 'and 28, which latches pointer 18 Aagainst counterclockwise rotation, thereby maintaining spring 57 in cocked position. Y

As soon as sand chamber 86 reaches the vertical position, the sand in the chamber begins to pass through orice 90 to start the timing operation. As the level of the sand in chamber 86 decreases, follower 94 moves downwardly about its pivotal axis with the decreasing level of the sand in the sand chamber, causing a downward pivotal movement of crank 110 and of cam follower 112 with respect to abutment 120. During the downward pivotal movement of crank 110, a slight clockwise circumferential movement of blade compartment 38 occurs due to the force of spring 57. During the delay period, follower 94 is maintained in constant engagement with the upper level of the sand in chamber 86 by the counterclockwise moment produced on crank arm 110 due to the biasing effect of spring 57 on blade compartment 38.

In the view shown in the drawing, the sand has nearly completely emptied from sand chamber 86 and cam follower projection 112 has nearly cleared the bottom edge of restraining lip 120. As soon as a small additional amount of sand has passed through orifice 90, projection 112 will clear abutment 120 and will permit the stored-up energy in spring 57 to forcibly move blade compartment 38 to off position, the clockwise movement of blade compartment 38 carrying the attached blade 64 to the axis 70.

When the blade compartment is released by the disengagement of cam follower 112 with abutment 120, the blade compartment 38 would move to off position with considerable speed since the upper sand chamber 86 is empty and the paddle 94 is free to oscillate. However, cam track portions 122, 124 and 126, with their irregular shape, provide a tortuous path for the cam follower 112 which checks what would otherwise be a rapid movement of the blade compartment 38, and provides a smooth deceleration of the blade assembly during its movement to off position.

The cycle of operation which has been described has carried the pointer 18 from off position to on position to delay position, and has carried pointer 16 to off position. By the end of the delay period, chamber 86 has become emptied of sand, and chamber 88 has become lilled with sand. When switch blade 64 is moved to its off axis 70 at the end of the delay period by the spring action, sand chamber 88 is moved sub- .stantially 45 degrees past its position as shown in Fig. 5, where it will then be in a position ready to duplicate the cycle of operations just described for sand compartment 86.

There is shown in Figs. 8-l0 a modified and preferred embodiment of the invention in which the rotatable compartment holding the flowable material is moved to its timing positions by means of a pivoted lever member rather than by use of a rotatable operating member as in the form previously described. The modified embodi- -ment of the time delay switch is adapted for use either as a conventional instant cut-off switch or as a time delay cut-off switch as desired.

Referring now to Figs. 8-l0, the modied time delay switch is generally indicated at 130 and includes a rotatable compartment generally indicated at 132. Compartment 132 is of generally hourglass shape and includes a pair of chambers 134 and 136 preferably formed of metal andl joined by a narrow neck portion 138 on .the interior of which is positioned Va grommet 140 having an oriiice 142. A owable material, preferably sand 144, sutiicient to lill one of the chambers, is disposed within rotatable container 132. Each of the chambers 134 and 136 is closed by means of a iiexible diaphragm member 146 and 148, respectively. Each of the diaphragm members 146 and 148 is provided with a rim portion 150 which is adapted to engage a circular bead 152 provided on each of the respective chambers 134 and 136. Each diaphragm 146 and 148 is also provided at the central portion of its outer'surface with a'button 153 which serves as a bearing surface for a follower member to be hereinafter described.

Rigidly secured to the outer surface of compartment 132 on each side thereof are a pair of spaced bracket members generally indicated at 154 and each including a pair of oppositely extending bracket portions 156 and 158 joined by a connecting portion 161). Bracket members 154 in effect constitute the side walls of compartment 132. Pivotally supported between the pair of spaced bracket portions 156 is a foliower member 162, the outer end of which is adapted to rest on the outer surface of button 153 of diaphragm 146 when chamber 134 is in the vertical position shown in Figs. 8 and 9. A similar follower member is pivotally supported between spaced bracket portions 15S, follower 170 being engageable with the button carried by diaphragm 148 when chamber 136 is in vertical position. A lip member 164 is rigidly connected to follower 162 adjacent a side edge thereof and extends angularly outwardly therefrom adjacent the pivot point of the follower to cooperate with a stationary abutment 181? interposed in the path of the lip member. A similar lip member 171 is carried by follower 17d to cooperate with abutment when chamber 136 is in vertical position. The movement of follower 162 away from the outer surface of diaphragm 146 when container 134 is in the down position is limited by a lip member 166 formed on the outer edge of each bracket portion 156. A similar lip member 16S is provided on the outer edge of each of the opposite bracket portions 158 adjacent chamber 136 to limit the downward movement of follower member 170 when chamber 136 is in down position as shown.

The rotatable container 132 is supported for rotating by spaced support members 172 and 174 which are respectively disposed adjacent the opposite surfaces of rotatable container 132. Support members 172 and 174 are in turn supported by a main support member 176 which is adapted to be securely fastened to a conduit box (not shown).

Support member 172 includes a vertically upstanding arm portion 178 which carries abutment 180 disposed in the path of movement of lip member 164 carried by follower member 162 when chamber 134 is in uppermost position as shown in the drawings, or in the path of lip member 171 carried by follower member 178 when chamber 136 is in uppermost position. A exible leaf spring 182 is rigidly connected, as by riveting, at point 184 to an intermediate point on support member 172. The function of leaf spring 182 is to prevent reverse or clockwise movement of rotatable compartment 132 due to the weight of the sand when the compartment is in horizontal position. To prevent such clockwise movement of the compartment, lip 164 or lip 171 engages the bottom edge 183 of leafV spring 182 when the compartment is in horizontal position.

Compartment 132 is supported for rotation about a horizontal axis substantially coincident with the center of oriiice 142. Chambers 134 and 136 are formed slightly off center with respect to the axis of rotation to permit the bracket arms 156 and 158 to rotate within the circle indicated at C.

To effect movement of rotatable compartment 132, a ratchet wheel generally indicated at 186 is disposed adjacent the outer surface of a support member 174. Ratchet wheel 186 is rigidly secured to the bracket 154 nearest support member 174 by means of a pin or rivet 188 which passes through support 174. Thus, ratchet wheel 186 and rotatable compartment 132 are rigidly connected together and turn as a unit so that rotation imparted to ratchet wheel 186 causes a corresponding rotation of rotatable compartment 132. Ratchet wheel 186 is providedV with four arms respectively indicated at 190, 192,

A:194 and 196 which are spaced apart from each other-by 90 degrees.

Rigidly connected to the right-hand or inner end of support member 174, with respect to the view shown in Fig. 8, is a contact support plate generally indicated at 198 and including a pair of arcuate contact plates 200 and 202 which are respectively connected to conductors 204 and 206. Contact plates 200 and 202 areprovided with a raised portion 203 intermediate theirV length to provide a snap action in moving from on to delay or delay to 011. Spaced below the arcuate contact members 200 and V.202 is an insulating section V204 provided with a raised portion y207 for imparting a snap action .during the operation of the switch from 01T to on or -on`to ott as will be described more fully.

Cooperating with the rotary ratchet wheel 186 is a lever member generally indicated at 208 pivoted at 'point 210 and provided with an operating handle 212 which Yprojects through the forward support member 176 landthrough a slot 215 in face plate 214 disposed vforwardly of support member 176. An electrically conducting bridging member 216 is carried at theinner-or right-hand end of lever 208 and is adapted to bridge the arcuate contact members 200 and 202 when in the position. shown in Fig. 8u to .thereby close the electrical circuit between conductors -204 and 206. When lever'208 is in a position such that bridging `member 216 is disposed on the insulating portion V207, the circuit between con- Vductors 204 and '206 is interrupted. A spring member 218 is connected to lever 208 at a point spaced inwardly .from pivot point 210 and normally tends to move lever 208 `to the position shown in dotted outline in which bridging member 216 ison the insulating portion 207 .ofcontact support plate 198vand operating handle 212 of the llever member is disposedat the upperendof the ,-slot.215 in face panel 214.

Rigidly fixed. to lever 208 intermediate pivot point 210 vand bridging member 216 are a pair of ratchetarms .220 vand 222, respectively, which are adapted to cooperate -with the rotatable ratchet wheel V186 to effect movement of the rotatable compartment 132. Each of the ratchet arms 220 and 222 isformed of resilient material and is provided with a laterally projecting edgeportion indicated at 224 and 226'on the respective ratchet anns Vv220 and 222 and best seen in the view of Fig. 10. Later- Yally lprojecting edge portions 224 and 226 constitutepawls which cooperate with ratchet wheel 186.

Operation of the modiedembodment The operation of the modified embodiment of'Fi'gs. 8 and -9 will-now be described. When the-switch 130 of Figs. 8 and 9 is in off position, operating lever1208 is in the dotted outline position shown in Fig. 8 in ywhich the operating handle 212 is disposed at the *uppereend of slot .215 and the slidable bridging member 216 is disposed on the insulating section 207 of contact support plate 198. ln this position, an open circuit exists between conductors 204 and 206. In this position of the switch, the lip 171 of follower member 170 'engages the bottom edge yor lip 183 of spring latch l182 and the chamber 134 which is filledwith sand is in athorizontal position.

To move the switch to on position, the operating handle 212 of lever l208 is pushed down to a substantially horizontal position to thereby cause bridging member 216 carried by the opposite end of lever .208 to snap across the raised portion 209 on insulating portion 207 and into bridgingrelation between the lower. ends of arcuate contact members 200 and 1202. This movement from fotf to on positionstilldoes not move the ratchet arms .220 and 222 into engagement with the ratchet twheel186 sothat the rotatablechamber 132 remainsin the dotted .outlinefhorizontaL position shown in Fig. .-9.

.If it should be desired to turn the switch back-to foff Y position in the conventional instant cut-off manner, operating handle 212 is moved from its horizontal intermediate position upwardly to the upper extreme of slot 215, as shown in dotted outline in Fig. 8, to thereby move bridging member 216 from its bridging engagement across the lower ends of contact members 200 and-202 and back onto the insulating portion 207. During this movement from on to oth the bridging member .216 moves across the raised portion 209 to impart aisnap action to the ott movement of the switch. Thus, in the normal olf-on and on-ott action of the switch, the rotatable compartment 132 is not affected and remains in horizontal position shown in dotted outline in Fig. 9.

If it should be desired to have the switch cut off with a delayed action, operating handle 212 is moved-from the horizontal intermediate on position to the ldelay position shown in full line in Fig. 8. This rcauses the sliding bridging member 216 to move with a snap action across raised portion 203 on arcuate contacts 200v and 202 to the upper end of arcuate contacts 200 and 202 as shown in Fig. 8 and also causes pawl portion 226 of ratchet arm 222 to engage the trailing edge of arm`192 of ratchet wheel 186 to drive ratchet wheel 186 in'a counterclockwise direction through an angle of degrees. In the view shown in Fig. 8, this 90 degree counterclockwise movement of ratchet wheel arm 192 has been completed. At the beginning of the movement just described, arm 192 was in the position occupied by arm 194 in the drawing of Fig. 8.

As ratchet wheel 186 rotates through the 90 degree angular movement just described due to the movement of lever 208 to the delay position, arm 190 of the ratchet wheel 186 has also advanced 90 degrees from the position occupied by arm 192 in Fig. 8. At the completion of the 90 degree angular movement just described, pawl portion 224 of ratchet arm 220 snaps in position behind the trailing edge of ratchet wheel arm 190. The resiliency of arm 220 permits arm 220 and its laterally bent pawl portion 224 to ride across the Surface of ratchet wheel arm 190 during the counterclockwise movement of arm 190 to the position shown in Fig. 8.

Movement of lever 208 to the delay position shown in Fig. 8 strongly tensions spring 218, the tension on spring 218 tending strongly to urge ratchet wheel 186'in a counterclockwise direction beyond the position shown in Fig. 8. However, spring 218 is prevented from causing such counterclockwise motion due to the engagement of lip 164 on follower 162 with abutment 180 carried by support member 172.

The movement of lever 208 to the delay position moves rotatable container 132 from a horizontal to the vertical position shown in full line in Figs. 8 and 9 and causes the sand filled chamber 134 to begin its timing action. Follower 162 bears against the button 153 at the central portion of diaphragm 146 and follows the level of the sand in chamber 134- as it decreases in height due to the passageof sand through orice to lower sand chamber 136. When the sand in the uppermost sand chamber 134 reaches a predetermined level, the diaphragm 146 having constantly followed that level, Vvlip 164 on follower 162 is moved to a position in which it can clear abutment 180. When this occurs, spring 218 pulls lever V208 downwardly and causes bridging member 216 to pass from arcuate contact portions 200 and 202 onto the insulating portion 207. At the Sametime, the downward'movement of lever 208 causes pawl 224 on ratchet arm 220 acting on arm of the ratchet wheel to drive ratchet wheel 186 through a movement of 90 degrees until lip 164 engages the bottom edge of spring latch 182. The sand chamber 136 which will then be filled with sand is moved to a .horizontal Vposition 9() degrees counterclockwise from that shown in Fig. 9 and in readiness for the next delay operation.

It can be seen from the foregoing that there is provided in accordance with this invention an improved time delay switch utilizing the changing level of owable material, such as hourglass sand, to control the release of a power means such as a spring having stored energy to move the switch to off position. This is in contrast to most time delay switch devices using a flowable material in which the weight of the sand is used to actuate the switch mechanism.

The delay action switch device of the invention is simple and rugged in construction and very reliable in operation. Furthermore, the switch of the invention may be used selectively as a conventional instant cut-oif switch or as a time delay switch as desired.

lThe modified preferred embodiment of the invention has the advantage that it is adapted to be operated by a conventional up-down movement of an operating lever as is customary in most residential installations.

While there have been shown and described particular embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention and, therefore, it is aimed to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as my invention is:

l. A time delay switch comprising a stationary housing, fixed electrical contact means carried by said housing, a receptacle mounted for movement in said housing, electrical contact means movable with said receptacle and engageable with said fixed Contact means, said receptacle having a chamber containing a iiowable material, means for causing said flowable material to iiow from said chamber at a predetermined time rate, spring means urging said receptacle to move to a predetermined position, cooperating latch means carried by said receptacle and by said housing to prevent movement of said receptacle to said position, and a follower movably mounted upon said receptacle responsive to the level of the flowable material in said chamber for releasing said latch means to thereby permit said spring means to move said receptacle to said predetermined position.

2. A time delay switch comprising a stationary housing, fixed electrical contact means carried by said housing, a receptacle mounted for movement in said housing, electrical contact means movable with said receptacle and engageable with said fixed contact means, said receptacle having a chamber containing a owable material, means for causing said iiowable material to ow from said chamber at a predetermined Atime rate, a follower means disposed in said receptacle in contact with said material in said chamber, a spring urging said receptacle to move to a predetermined position relative to said stationary housing, a latch means movable with said follower and engageable with an abutment carried by said housing to prevent movement of said receptacle to said predetermined position, said latch means being movable to a position Where it clears said abutment upon a predetermined movement of said follower means to thereby permit said spring means to move said compartment to said predetermined position.

3. A switch device selectively movable to a predetermined position with either an immediate action or a time delay action comprising a movable electrical contact member cooperating with a fixed electrical Contact means, said Contact member being movable to said predetermined position along a first path with an immediate action, said contact member being movable to said predetermined position along a second path, restrainingV means located along said second path and effective to delay the movement of said contact member to said predetermined position, and timing means movable with said contact member for rendering said restraining means ineffective after a predetermined time delay whereby said Y 12 YcontactY member may move to said predetermined position.

4.V A switch device selectively movable to a predeter mined position with either an immediate action or a time delay action comprising a movable receptacle, an electrical contact member carried by said receptacle and cooperating with a xed electrical contact means, said receptacle being movable to said predetermined position along a first path with an immediate action, said receptacle being movable to said predetermined position along a second path, restraining means located along said second path and effective to delay the movement of said receptacle to said predetermined position, and timing means carried by said receptacle for rendering said restraining means ineective after a predetermined time delay whereby said receptacle may move to said predetermined position.

5. A time delay device comprising a movable receptacle containing a fiowable material, a chamber in said receptacle, means for causing fiowable material to flow from said chamber at a predetermined time rate, a reciprocable lever means for moving said receptacle to a position in which said fiowable material may flow from said chamber at said predetermined time rate, a spring urging said receptacle to move to a predetermined position from said position to which it is moved by said lever, latch means preventing movement of said receptacle to said predetermined position, and means responsive to the level of the owable material in said chamber for releasing said latch means to thereby permit said spring to move said receptacle to said predetermined position.

6. A time delay device comprising a movable receptacle containing a flowable material, a chamber in said receptacle, means for causing flowable material to fiow from said chamber at a predetermined time'rate, a reciprocable lever for moving said receptacle to a first position in which said owable material may flow from said chamber at said predetermined time rate, a spring urging said receptacle to move to a second position from said first position, cooperating means carried by said lever and by said receptacle to maintain said lever in a fixed position while said receptacle is in said first position, said spring urging said lever away from said fixed position to a predetermined position, latch means preventing movement of said receptacle to said second position, and means responsive `to the -level of the flowable material in said chamber otally mounted adjacent said receptacle and carrying pawl `means engageable with said ratchet member, said lever member being movable to cause said pawl means to engage said Vratchet member to move said receptacle to a position in which said flowable material may ow Aby gravity from said chamber, a spring urging said receptacle to move to a predetermined position other than said position in which said material is owable from said cha-mber, restrainingV means preventing movement of said receptacle to said position, and means responsive to the level of the flowable material in said chamber for render- Ving ineffective said restraining means to thereby'permit said spring to move said receptacle to said predetermined position.

8. A time delay electric switch comprising a movable receptacle member containing a flowable material, a chamber in said receptacle member, means for causing fiowable material to flow from said chamber at a predetermined time rate, a reciprocable lever member for moving said receptacle member to a position in which said owable material may llow from said chamber at said predetermined time rate, a spring urging said receptacle member to move to a predetermined position from said position to which it is moved by said lever, latch means preventing movement of said receptacle member to said predetermined position, means responsive to the level of the owable material in said chamber for releasing said latch means to thereby permit said spring to move said receptacle member to said predetermined position, and an electric switch means `carried by one of said members and moved to a given position by said spring upon release of said latch means.

9. A time delay electric switch comprising a movable receptacle containing a owable material, a chamber in said receptacle, means for causing owable material to flow from said chamber at a predetermined time rate, a reciprocable lever for moving said receptacle to a position in which said owable material may ow from said chamber at said predetermined time rate, electrical switch means carried by said lever, a spring urging said receptacle to move to a predetermined position from said position to which itis moved by said lever, latch means preventing movement of said receptacle to said predetermined position, cooperating means carried by said lever and by said receptacle to maintain said lever in a xed position while said latch means prevents movement of said receptacle, and means responsive to the level of the owable material in said chamber for releasing said latch means to thereby permit said spring to move said receptacle to said predetermined position and to move said lever away from said xed position whereby electrical circuit connections are changed by said switch means.

10. A time delay device comprising a stationary housing, a receptacle rotatably supported within said housing, said receptacle including a pair of diametrically opposed communicating chambers containing owable material, a follower pivotally mounted upon said receptacle adjacent each of said chambers for movement within the associated chamber in accordance with the level of flowable material therein, a cam track mounted upon said stationary housing, a projection on each of said followers engageable with said cam track, means for rotating said receptacle to a iirst position wherein one of said chambers is located above the other to thereby permit said flowable material to flow from said one of said chambers to the other, a latching abutment on said cam track engageable with the projection on the follower associated with said one chamber when said receptacle is moved to said rst position, land spring means ybiasing said projection against said abutment and thereby biasing said follower against the owable material within said one chamber, y'said abutment being oriented to engage said projection until the material within said one chamber falls below a predetermined level at which said follower pivots said projection clear of said abutment to thereby permit said receptacle to be rotated from said tirst position by said spring means.

11. A time delay device as recited in claim 10 including means on said cam track for controlling rotation of said receptacle from said rst position by said spring means.

References Cited in the le of this patent UNITED STATES PATENTS 923,129 Schweitzer May 25, 1909 1,158,586 Thornton Nov. 2, 1915 2,259,402 Van Dam Oct. 14, 1941 2,365,072 Hagner Dec. 12, 1944 2,507,949 Asder May 16, 1950 

